Voters in eastern Bolivia are casting ballots in an autonomy referendum the federal government has declared as illegal. VOA's Brian Wagner reports the vote is testing the nation's coalition government and may threaten national stability.

Leaders in the powerful eastern department of Santa Cruz have called the vote in an effort to gain greater control for financial and political decisions in the region. The vote is not expected to be legally binding, but supporters say if approved the measure will create new leverage to negotiate with federal officials.

President Evo Morales has declared the vote illegal and said it threatens national integrity. But he has dismissed concerns about violent clashes, and said he will not send troops to block the vote.

Critics of the vote accuse business leaders in the east of trying to stop tax money from going to impoverished communities in the west, including many indigenous villages. Referendum supporters say some of that money should benefit needy residents in the east.

Mount Saint Mary's University Political Science Professor Miguel Centellas says the autonomy vote has split the nation along economic, social and racial lines.

"The argument has been simply we have all the oil resources, natural gas. It is really the part of the country that really is the dynamic engine of growth," said Centellas. "It picks up the slack for the weak economy in places like Potosi, Ororo, and even to some extent, large parts of La Paz."

Centellas adds the autonomy movement is not new, and has been brewing for generations, in part to strengthen what some view as weak government at the department [state] level. One measure was defeated in a nationwide vote in 2006, when four eastern departments backed autonomy and five others rejected it.

The latest vote comes at a delicate moment for the government, as recent polls show a dip in approval ratings for Mr. Morales. The president has led a drive to write a new constitution, but the process is stalled because of the autonomy issue and other disputes.

Professor Raul Madrid, of the University of Texas at Austin, says there is concern that simmering tensions may explode.

"They are moving into uncharted territories, and I am fearful this could end up being resolved in the streets with protests back and forth," said Madrid.

Three other eastern departments are expected to vote on the autonomy initiative in coming weeks, and leaders in two others are expected to consider votes as well.

Madrid says recent government reforms have raised concern among business leaders in the east and elsewhere. He says they take issue with plans for widespread agrarian reform, and last week's announcements of the nationalization of the national telephone company and a key foreign oil business.

But the professor says Mr. Morales is also feeling pressure from leftist leaders calling for him to make even broader reforms.

"Certain sectors of the population want him to move much more radically than he has done so far, and he is reluctant to do that. They are getting frustrated with him," said Morales. "There are other sectors of the population that want much more moderate policies."

Madrid says the autonomy vote is placing new pressure on the government's fragile coalition, which is already showing signs of strain.